Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Breast: Radiologic-Pathologic Correlation

Abstract Papillary Endothelial Hyperplasia (PEH, Masson’s Tumor) is a benign lesion of vascular origin that is rarely identified in the breast. PEH is thought to be a variant of organizing thrombus. We identified 28 cases of PEH in the literature, and we describe an additional three cases below. Previous studies have reported PEH appearance as circumscribed masses and/or microcalcifications. Histopathologically, PEH is a lesion comprised of proliferating endothelial cells within an area of organizing hemorrhage and fibrin, often forming papillary structures with a hyalinized fibrin core. Surgical excision is typically recommended because PEH can mimic angiosarcoma histologically in a small biopsy.